Spark plasma sintering of titanium-coated diamond and copper-titanium powder to enhance thermal conductivity of diamond/copper composites

Diamond/copper (Cu) composites are fabricated using a mixture of titanium (Ti)-coated diamond and composite of Cu-Ti powders, which is proposed to improve interfacial bonding between diamond particles and Cu matrix for diamond/Cu composites. Suitable coating and composite of Cu-Ti powders in the sintering process are optimized. The microstructures, structure of the interface, thermal properties, and relative density of diamond/Cu composites are investigated. Results show that the interfacial bonding of composites could be strengthened. The relative density of diamond/Cu composites is 99% in a volume fraction range of diamond between 40% and 65%. Moreover, 50 vol% diamond/Cu composites sintered at 1000 degrees C for 5 min exhibit a thermal conductivity as high as 630 W/(m K). This value is approximately 80% of the theoretical value. A high thermal conductivity is achieved because of the formation of the diamond/TiCiTi/CuTi/Cu structure at the interface between diamond and Cu. (C) 2015 Elsevier Ltd. All rights reserved.